Riverstone Networks WICT1-12 - Manual (Page 324)

17-16 Riverstone Networks RS Switch Router User Guide Release 8.0
RSVP Configuration MPLS Configuration
The path-refresh-interval and resv-refresh-interval are the periods of time between the generation of successive refresh
messages by an RSVP neighbor. The path-refresh-interval or resv-refresh-interval is set locally at each RSVP router;
this value is sent to neighbor routers in Path and Resv messages, respectively. The receiving RSVP node uses the values
contained in the messages to calculate the path-lifetime or resv-lifetime for the path or reservation state. On the RS, the
default interval for both Path and Resv refreshes is 30 seconds.
The path-multiplier and resv-multiplier are integers between 1 and 255 that are configured on the local router. On the
RS, the default for both multipliers is 3.
For example, if the path-multiplier is set locally at 3 and the path-refresh-interval received from an RSVP neighbor is
30 seconds, then:
path-lifetime = 3 * 30 = 90 seconds
[path-multiplier minus 1] successive Path refresh messages may be lost without the path state timing out. For example,
the path-multiplier default value on the RS is 3; 2 successive Path refresh messages can be lost without the path state
timing out.
On the RS, you can use the
rsvp set global
command to set the values for the Path and Resv refresh intervals and
multipliers:
• The
path-refresh-interval
parameter specifies the interval at which RSVP sends out Path
messages to the downstream neighbor. The default value is 30 seconds.
• The
resv-refresh-interval
parameter specifies the interval at which RSVP sends out Resv
messages to the upstream neighbor. The default value is 30 seconds.
• You can specify a
path-multiplier
parameter value between 1 and 255. The default value is 3.
• You can specify a
resv-multiplier
parameter value between 1 and 255. The default value is 3.
17.3.3 RSVP Hello Packets
The RS supports the sending of RSVP hello packets on a per-interface basis. Sending hello packets allows RSVP
routers to detect the loss of RSVP state information of a neighbor node, for example, when a link fails or the neighbor
router restarts. RSVP hello packets can detect the state change of a neighbor node more quickly than simply relying
on RSVP soft state timeouts. For example, if a link fails, RSVP hello packets can detect the state change in about 20
seconds, compared to several minutes for an RSVP soft state timeout.
When hello packets are enabled on an interface, RSVP sends unicast hello packets to the RSVP neighbor on that
interface. On an RS interface, hello packets are sent by default at 3-second intervals. RSVP sessions with a neighbor
node are considered to be “down” if hello packets are not received within the following time period:
hello-interval * hello-multiplier
On the RS, the default for the hello-multiplier is 3. Thus, if hello packets are not received from a neighbor within 9
seconds, that neighbor and its RSVP session are considered to be down.
Sending RSVP hello packets is disabled by default on the RS. You can enable RSVP hello packets on an interface
with the
hello-enable
parameter of the
rsvp set interface
command. For example, the following command
enables RSVP hello packets on the interface ‘int2’:
rsvp set interface int2 hello-enable